If you look at a map of the US power grid, it looks like a spider web blanketing the entire country. It’s a patchwork that formed after communities that got their power locally were slowly stitched together to create a massive network. So could we scale that up even bigger? Could we connect the entire world with power lines? What would that do for us, and what would it look like?

The most obvious technological hurdle is transmitting power over extremely long distances, which is something of a recurring theme. Back in the 1880s, when the first power plants were coming online, Nikola Tesla’s alternating current duked it out with Thomas Edison’s direct current in the war of the currents, the original AC/DC. AC eventually won out because at the time it was easier to convert AC power to higher or lower voltages, and higher voltages are needed to travel longer distances with less energy loss due to resistance.

But fast forward to the present day, and DC is making a comeback. Not just because it’s everywhere, since our phones, laptops, and anything with a battery runs on it. It’s also because it’s become a more viable method for long distance power transmission, thanks in large part to China’s geography.